1. Field of the Invention
The present invention relates to a light emitting diode package, more particularly, in which insulating layers are formed by anodizing on a portion of a thermally conductive board by anodizing and plated with a conductive material, thereby simplifying its manufacturing process and improving heat radiation efficiency, a circuit board for a light emitting diode and a manufacturing method thereof.
2. Description of the Related Art
A backlight for a mobile phone, a navigation system and a personal digital assistant (PDA) mainly adopts a light emitting device using a light emitting diode which is long in useful life and can be reduced in size. The light emitting device using the light emitting diode is more advantageous than a light emitting device using a cold cathode fluorescent lamp (CCFL). That is, the light emitting diode (LED) is environment-friendly, quick to respond to with a rate of several nano seconds, thus assuring higher color reproductivity. Also, the LED is adjustable in its light amount to arbitrarily alter brightness and color temperature.
The light emitting device using the light emitting diode is largely constructed of a circuit board having a current pattern formed thereon, and a light emitting diode disposed on the circuit board. Recently, with a high-output light emitting diode commercially viable, there has arisen a demand for the circuit board capable of radiating heat generated from the light emitting diode more effectively.
A conventional light emitting device using a light emitting diode will be explained with reference to the accompanying drawings.
FIG. 1 is an exploded perspective view illustrating the conventional light emitting device.
As shown in FIG. 1, the light emitting device 1 includes a circuit board 3 with a current pattern formed thereon, a light emitting diode 6 disposed on the circuit board 3 and a reflective member 2 for guiding direction of light from the light emitting diode.
The circuit board 3 is made of an insulating material and a pair of electrodes 4a and 4b are formed at opposing sides to be electrically connected to the outside. Conductive patterns 5a and 5b of e.g., a copper foil are formed on a top surface of the circuit board 3. The conductive patterns 5a and 5b are electrically connected to the electrodes 4a and 4b, respectively and extended toward a center of the top surface of the circuit board body 3. Moreover, fixed electrode patterns 7a to 7d made of e.g., the copper foil, are provided at each corner of the top surface of the circuit board 3. Here, an insulating film 8 may be provided on the electrodes 4a and 4b and the conductive patterns 5a and 5b to insulate the top surfaces thereof.
The reflective member 2 is made of a resin such as a heat-resistant high-performing plastic or a metal such as copper and aluminum. The reflective member 2 has a reflective through hole 2a perforated in a central portion thereof to seat the light emitting diode 6. An inner wall of the reflective through hole 2a is bright-plated with silver or nickel to enhance reflectivity of light emitted from the light emitting diode 6. Here, the reflective member may be bright-plated on all sides thereof.
The reflective member 2 and the circuit board body 3 are sized substantially identical to each other.
The light emitting diode 6 is disposed in a mounting area 3a, i.e., the central portion of the top surface of the circuit board 3. Although not illustrated, an anode and a cathode are electrically connected to the conductive patterns 5a and 5b, respectively.
Accordingly, current applied to the circuit board 3 flows to the light emitting diode 6 through the electrodes 4a and 4b, and the conductive patterns 5a and 5b so that the light emitting diode 6 emits light upward.
Heat generated from the light emitting diode 6 is radiated through the circuit board 3, that is, an insulating member connected to an underside surface of the light emitting diode 6. In general, since the insulating material is very low in thermal conductive efficiency, the conventional light emitting device 1 structured as above cannot radiate heat from the light emitting diode 6 effectively.
In an attempt to overcome the problem, a circuit board has been proposed, in which a through hole is perforated in an area where the light emitting diode 6 is disposed, and filled with a thermal conductive material. Yet this structure complicates a manufacturing process, and limitedly enhances heat radiation efficiency due to contact of the thermal conductive material with only a portion of the underside surface of the light emitting diode.
In addition, in the circuit board body 3 configured as above, the electrodes 4a and 4b, conductive patterns 5a and 5b and the insulating layer 8 should be fabricated separately. This renders the manufacturing process cumbersome, increases manufacturing costs and significantly undermines productivity.